From my previous post Setup Your Google App Engine Application To Use Your Own Domain, you can use Google App Engine as CDN and use your subdomain as alias to Google App Engine application. So instead of using this url: [application-id].appspot.com you can use cdn.domain.com. It looks neater and more professional.
But after I use my custom domain to serve my Google App Engine application, it seems like Google doesn’t count the bandwidth and billing. See this screenshot:
I don’t know why this strange behavior happens. Is this a Google App Engine and Google Apps bug? I’m not sure, but if I use a custom domain, I will never exceed my bandwidth anymore and don’t have to pay for billing for over quota. That’s very good news 🙂
Well I don’t know when Google will fix this, but until now I’m still using Google App Engine for free and never over quota! Thanks Google 🙂